For Boston area, we stayed at Fourth Cliff and Hanscom Fam Camp. I know no help for you BUT, for touring, visit USS Constitution. Salem, Salem Witch trial museum (very sad when mobs rule).
Take a HoHo bus ride around downtown.
Tour Cape Cod. Provincetown is really neat.
You mentioned heading NE in the spring.
Bar Harbor Maine is fantastic. We stayed at Bar Harbor Campground. Closest to Acadia NP. In ANP they have 157 miles of hiking trails. 47 miles of Carrage roads (bike roads). We take our ebikes and go riding every day. We spent 2 months there. Loved it. Tour Schoodic Peninsula.
If you go up into Canada tour Nova Scotia and Prince Edward Island. We spent two months up there. We will go again someday.
Daryl and Marianne,
2019 3130re 20th Anniversary Edition
2016 F350 Lariat